Lawn mowing apparatus with mower deck alignment sensors

ABSTRACT

A lawn mowing apparatus may include sensors that are fastened to both its mower deck and its chassis. The sensors may sense a position of the mower deck in relation to the chassis. The sensed position of the mower deck may be presented to the operator via a dashboard display of the lawn tractor or transmitted via a wireless signal to another device. Based on such sensed position, an operator of the lawn tractor may manually adjust the position of the mower deck until the sensed position of the mower deck is within an acceptable operating range. In some embodiments, servomotors may adjust the position of the mower deck until the sensed position of the mower deck is within an acceptable range.

FIELD OF THE INVENTION

Various embodiments relate to an apparatus for mowing a lawn, and moreparticularly, to sensing whether a mower deck of such an apparatus isproperly aligned.

BACKGROUND OF THE INVENTION

The correct position of the mower deck of a lawn tractor or riding lawnmower has a direct relationship to the quality of cut. In particular,poor positioning or alignment of the mower deck creates an uneven cut.While the mower deck may be proper positioned at the factory, the mowerdeck is likely to become misaligned as a result of use. Accordingly,periodic adjustment of the position of the mower deck may help maintaina quality cut.

Limitations and disadvantages of conventional and traditional approachesshould become apparent to one of skill in the art, through comparison ofsuch systems with aspects of the embodiments set forth in the remainderof the present application.

BRIEF SUMMARY OF THE INVENTION

Apparatus for mowing a lawn and methods for sensing alignment of a mowerdeck are substantially shown in and/or described in connection with atleast one of the figures, and are set forth more completely in theclaims.

Advantages, aspects and novel features of the present invention, as wellas details of an illustrated embodiment thereof, will be more fullyunderstood from the following description and drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

For clarity of illustration, exemplary elements illustrated in thefigures may not necessarily be drawn to scale. In this regard, forexample, the dimensions of some of the elements may be exaggeratedrelative to other elements to provide clarity. Furthermore, whereconsidered appropriate, reference labels have been repeated among thefigures to indicate corresponding or analogous elements.

FIG. 1 shows a lawn mowing apparatus in the form of a lawn tractorhaving a chassis and a mower deck.

FIG. 2 depicts a three-axis relationship of the position sensors for thechassis and mower deck of FIG. 1.

FIG. 3 shows details regarding a dashboard for the lawn tractor of FIG.1.

FIG. 4 provides a block diagram depicts aspects of a controller and itsrelationship to the dashboard and sensors of FIGS. 2-3.

FIG. 5 shows a flowchart for an example method which may be implementedby the controller of FIG. 4 in order to detect misalignment of the mowerdeck.

FIG. 6 shows a flowchart of an example method which may be implementedby the controller to detect improperly inflated tires of the lawntractor of FIG. 1.

FIG. 7 shows details of an example display that presents chassis andmower deck alignment information.

DETAILED DESCRIPTION OF THE INVENTION

Aspects of the present invention are generally related to an apparatusfor mowing a lawn, and more particularly, to sensing whether a mowerdeck of such an apparatus is proper aligned. The following descriptionfocuses upon an embodiment of a lawn tractor having a mower deck thatwhich may be used to mow a lawn. However, various aspects of thedisclosed sensing techniques may be applicable to a wider range of lawnmowing apparatus, such as, for example, self-propelled lawn mowers,riding lawn mowers, zero turn tractors, wheeled trimmers, and the like.

As described in more detail below, a lawn tractor may include sensorsthat are attached to or otherwise associated with a mower deck andchassis of the lawn tractor. The sensors may sense a position of themower deck in relation to the chassis. The sensed position of the mowerdeck may be presented to the operator via a dashboard display of thelawn tractor or transmitted via Bluetooth or other wireless signal toanother presentation device, such as a smart phone, tablet, desktop,laptop, display monitor, television, or other display device, forpresentation to the operator. Based on such sensed position, an operatorof the lawn tractor may manually adjust the position of the mower deckuntil the sensed position of the mower deck is within an acceptableoperating range. In some embodiments, servomotors may be used to adjustthe position of the mower deck until the sensed position of the mowerdeck is within an acceptable range.

By monitoring the position of the chassis, the chassis sensor mayindirectly monitor pressure in tires of the lawn tractor. Variances intire pressure may result in variances in the tilt of the chassis. Assuch, based on variances in a sensed position of the chassis, a tirepressure alert may be generated and presented to the operator. In someembodiment, a controller may generate one or more control signals thatcause a compressor to inflate tire(s) which are detected as beingunderinflated.

Referring now FIG. 1, an example embodiment of a lawn tractor 10 isshown. The lawn tractor 10 may include a chassis 12 supported by tworear wheels 14 and two front wheels 16 and their respective inflatabletires 18, 20. The lawn tractor 10 may further include a driver's seat 22and a steering wheel 24. The steering wheel 24 may be mechanicallycoupled to the front wheels 16 to provide steering control to anoperator sitting in the driver's seat 22.

As shown, the lawn tractor 10 may also include a mower deck 32 supportedby the chassis 12 via adjustable linkage 34. The mower deck 32 mayinclude one or more blades 36 for mowing a lawn. Furthermore, the lawntractor 10 may include an engine 38. The engine 38 may be mechanicallycoupled to the rear wheels 14, the front wheels 16, or both in order toprovide driving torque to such wheels 14, 16 and impart the lawn tractor10 with locomotion. The engine 38 may be further mechanically coupled tothe one or more blades 36 of the mower deck 32 to rotate the blades 36such that the blades 36 cut grass and mow the lawn.

The lawn tractor 10 further includes at least two position sensors 40,42. A first position sensor 40 is attached or otherwise affixed to thechassis 12 and a second position sensor 42 is attached or otherwiseaffixed to the mower deck 32. To this end, each of the position sensors40, 42 in one embodiment includes a gyroscopic sensor that senses thethree rotational axes of yaw, pitch, and roll for its respective chassis12 or mower deck 32. Moreover, the position sensors 40, 42 may generateone or more signals indicative of the sensed rotational axes. In otherembodiments, the position sensors 40, 42 may be implemented using othertypes of sensors such, for example, linear position sensors, angularsensors, tilt sensors, Hall effect sensors, rotary position sensors,inclinometers, clinometers, and multi-axis position sensors.Furthermore, the adjustable linkage 34 may only permit adjustments tothe pitch and roll of the mower deck 32. In such embodiments, theposition sensors 40, 42 may sense and generate signals only with respectto two rotational axes of interest, namely, pitch and roll.

As shown in FIG. 2, the first position sensor 40 may be attached to thechassis 12 such that the first position sensor 40 senses the yaw, pitch,and roll of the chassis 12. The pitch of the chassis 12 corresponds torotation of the chassis 12 about an X-axis that runs horizontallythrough a left side 13 and right side 15 of the chassis 12. The roll ofthe chassis 12 corresponds to rotation of the chassis 12 about a Y-axisthat runs horizontally through a front end 17 and rear end 19 of thechassis 12. The yaw of the chassis 12 corresponds to rotation of thechassis 12 about a Z-axis that runs vertically through a top side 21 andbottom side 23 of the chassis 12.

Similarly, the second position sensor 42 may be attached to the mowerdeck 32 in a manner that permits the second position sensor 42 to sensethe yaw, pitch, and roll of the mower deck 32. The pitch of the mowerdeck 32 corresponds to rotation of the mower deck 32 about an X-axisthat runs horizontally through a left side 33 and right side 35 of themower deck 32. The roll of the mower deck 32 corresponds to rotation ofthe mower deck 32 about a Y-axis that runs horizontally through a frontend 37 and rear end 39 of the mower deck 32. The yaw of the mower deck32 corresponds to rotation of the mower deck 32 about a Z-axis that runsvertically through a top side 41 and bottom side 43 of the mower deck32.

Referring now to FIG. 3, a perspective view of a dashboard 50 of thetractor 10 is shown. The dashboard 50 may include a display device 52that is configured to present information to an operator of the lawntractor 10. In some embodiments, the dashboard 50 may be configured toreceive a presentation device 54 such as, for example, a smart phone,tablet, or other portable computing device and mount such presentationdevice 54 to the lawn tractor 10. In such an embodiment, thepresentation device 54 may provide the display device 52 used to presentinformation to the operator of the lawn tractor 10. In otherembodiments, the presentation device 54 may comprises a smart phone,tablet, laptop, desktop, monitor, television or some other displaydevice distinct from the dashboard 50 and/or lawn tractor 10, which arecapable of receiving information from the lawn tractor 50 and presentingsuch information to an operator of the lawn tractor 50.

Referring now to FIG. 4, additional details concerning the dashboard 50and a control aspects of the lawn tractor 10 are shown. As shown, thedashboard 50, regardless of whether implemented with a separatedpresentation device 54 or as an integrated display, may include acontroller 64 having a processor 66, a memory 68, and a wirelesscommunications interface 70. The memory 68 may store instructions andother information to be executed or used by the processor 66.

The processor 66 may be configured to execute and access theinstructions and other information stored in the memory 68. In responseto such execution, the processor 66 may control the display ofinformation on display device 52. Additionally, the processor 66 mayreceive input from the operator of the lawn tractor via one or more userinput devices 72 of the dashboard 50. For example, the processor 66 mayreceive input via a button, keypad, touch screen, or other device of theuser input devices 72.

As shown, the lawn tractor 10 may further include another controller 80.The controller 80 may also include a processor 82, a memory 84, and awireless communications interface 86. The memory 84 may storeinstructions and other information to be executed and used by theprocessor 82. The processor 82 may be configured to execute theinstructions and access the other information stored in the memory 84.

The wireless communications interface 86 of tractor controller 80 may beconfigured to send and/or receive wireless signals to/from the wirelesscommunications interface 70 of the dashboard controller 64.Additionally, the tractor controller 80 may also include a data port 88,such as, for example, a port or cable that may be used in the deliveryof information from the tractor controller 80 to dashboard controller64, another system, device, machine, or other non-transitorycomputer-readable storage medium. For example, the data port 88 may be aUSB port that permits a wired connection with a data port 74 of thedashboard 50.

The tractor controller 80 may be operably connected to the positionsensors 40, 42 that provide information relating to position of thechassis 12 and mower deck 32. Such connection between the tractorcontroller 80 and the sensors 40, 42 may include a wired connectionand/or a wireless connection, including, for example, through the use ofa Bluetooth enumerator bus. However, according to other embodiments, thesensors 40, 42 may include a transmitter, such as a smart sensor, thatallows for the transmission of information sensed by the sensor 40, 42to the tractor controller 80.

Information or data provided by the sensors 40, 42 may be used by theprocessor 62 of the tractor controller 80 to determine whether the mowerdeck 32 is properly aligned with the chassis 12. The processor 62 mayfurther determine from such information whether the tires of the lawntractor 10 are properly inflated.

The processor 62 may be further coupled to a plurality of servomotors 44associated with the linkage 34 and an air compressor 46 associated withtires 18, 20. In particular, the processor 62 may generate one or morecontrol signals to cause the servomotors 44 to adjust linkage 34 and theposition of the mower deck 32 with respect to the chassis 12. Similarly,the processor 62 may generate one or more control signals to cause theair compressor 46 to inflate one or more tires 18, 20 and adjust theposition of the chassis 12 with respect to the surface upon which thelawn tractor 10 is resting.

Referring now to FIG. 5, a flowchart is depicted for an example method500 for detecting whether adjustment of the mower deck 32 is warranted.As shown, the controller 80 at 510 may receive one or more signals fromthe position sensor 40 attached to the chassis 12. The signals receivedfrom the position sensor 40 may be indicative of a position of a chassis12. In particular, the signals may be indicative of the tilt or the yaw,pitch, and roll of the chassis 12. At 520, the controller 80 may receiveone or more signals from the position sensor 42 attached to the mowerdeck 32. The signals received from the position sensor 42 may beindicative of a position of a mower deck 32. In particular, the signalsmay be indicative of the tilt or the yaw, pitch, and roll of the mowerdeck 32.

At 530, the controller 80 may determine, based on the signals receivedfrom the position sensors 40, 42, a relative position of the mower deck32 with respect to the chassis 12. To this end, the controller 80 maysubtract values for the yaw, pitch, and roll of the mower deck 32 fromvalues for the yaw, pitch, and roll for the chassis 12 to obtaindifferential yaw, pitch, and roll values that are indicative of adifference in tilt between the chassis 12 and the mower deck 32.

The controller 80 at 540 may determine, based upon the determinedrelative position of the mower deck 32 to the chassis, whetherrealignment of the mower deck is warranted. To this end, the controller80 may determine that realignment is warranted in response todetermining that the difference in tilt, yaw, pitch, or roll between thechassis 12 and the mower deck 32 is greater than a respective threshold.

If the controller 80 determines at 540 that realignment is warranted,the controller at 550 may notify the operator that realignment of themower deck 32 is warranted. To this end, the controller 80 may transmitone or more signals to the dashboard 50 to cause the dashboard 50 todisplay or otherwise present a notification that realignment of themower deck 32 is warranted. Regardless of whether realignment iswarranted, the controller 80 at 560 may transmit one or more signals tothe dashboard 50 or presentation device 54 to cause the dashboard 50 orpresentation device 54 to present information regarding the currentpositions of the chassis 12, the mower deck 32, and an amount ofadjustment, if any, needed in order to properly align the mower deck 32.See, for example FIG. 7 which presents an example presentation.

As shown in FIG. 7, the dashboard 50 may present the front to back angleor pitch of the chassis 12 and the side to side angle or roll of thechassis 12 in degrees. Similarly, the dashboard 50 may present the frontto back angle or pitch of the deck 32 and the side to side angle or rollof the deck 32 in degrees. Moreover, the dashboard 50 may present thedifference between the tilt of the mower deck 32 and the chassis 12 as anumber of degrees the mower deck 32 is to be adjusted front to back(e.g., its differential pitch) and to be adjusted side to side (e.g.,its differential roll). Furthermore, the dashboard 50 may present abulls-eye chart 90 which graphically depicts the differential pitch anddifferential roll between the chassis 12 and mower deck 32 as a point 92on the chart. Such a depiction may aid an operator to better understandthe adjustment needed in order to bring the point 92 back to center.

Referring now to FIG. 6, a flowchart is depicted for an example method600 for indirectly testing the tire pressure of the one or more thetires 18, 20. To this end, the operator at 610 may place the lawntractor 10 on a level surface in order to return the lawn tractor 10 toa known reference point to which the lawn tractor 10 was calibratedduring manufacture. In some embodiments, the controller 80 may permitthe operator to recalibrate the reference point to a different surface,which may not be level, by having the operator place the lawn tractor 10on such surface, and then request recalibration via one or more userinput devices 72. At 620, the controller 80 may receive, via one or moreof the user input devices 72, a request from the operator to test orcheck the tire pressure of the one or more tires 18, 20.

In response to such request, the controller 80 at 630 may receive one ormore signals from the position sensor 40 attached to the chassis 12. Thesignals received from the position sensor 40 may be indicative of aposition of the chassis 12. In particular, the signals may be indicativeof the tilt or the yaw, pitch, and roll of the chassis 12 with respectto the reference point associated with the surface.

At 640, the controller 80 may determine, based on the signals receivedfrom the position sensor 40 attached to the chassis 12 whether one ormore tires 18, 20 may be improperly inflated. To this end, thecontroller 80 may determine that one or more tires 18, 20 may beimproperly inflated in response to determining that the tilt, yaw,pitch, or roll of the chassis 12 with respect to the reference point isgreater than a respective threshold. If the tires 18, 20 are properlyinflated, the chassis 12 should be level when the lawn tractor 20 isplaced on a level surface. Thus, if the controller 80 determines thatthe chassis 12 is not within an appropriate operating range of beinglevel, then one or more of the tires 18, 20 may be improperly inflated.As such, the controller 80 at 650 may transmit one or more signals tothe dashboard 50 to cause the dashboard 50 to display or otherwisepresent a notification that the air pressure of one or more tires 18, 20may be improper. Regardless of whether the controller 80 detects thatthe chassis 12 is not within an appropriate operating range, thecontroller 80 at 660 may transmit one or more signals to the dashboard50 or presentation device 54 to cause the dashboard 50 or presentationdevice 54 to present information regarding the current position of thechassis 12. The operator based on such presented information may verifythe alignment of the chassis 12 or determine which tire 18, 20 toinflate.

In above describe embodiment process 600, the controller 80 notifies theoperator when the chassis 12 is misaligned due to improper tirepressure. However, in some embodiments, the controller 80 in response tosuch a determination may generate one or more control signals whichcause compressor 46 to inflate one or more tires 18, 20. By inflatingone or more tires 18, 20 via compressor 46, the controller 80 maycorrect the alignment of the chassis 12 such that the chassis 12 iswithin the appropriate operating range.

While the present invention has been described with reference to certainembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the appended claims. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the disclosed embodiments without departing from itsscope. Therefore, the appended claims are not to be limited to theparticular embodiment or embodiments disclosed, but to encompass allembodiments falling within their scope.

What is claimed is:
 1. A lawn mowing apparatus, comprising: a chassis; aplurality of wheels coupled to the chassis and configured to support thechassis above a lawn; a mower deck comprising a blade for mowing thelawn; an adjustable linkage that couples the mower deck under thechassis and carries the mower deck in a cutting position above the lawn;a first position sensor coupled to the chassis and configured togenerate first signals indicative of a position of the chassis; a secondposition sensor coupled to the mower deck and configured to generatesecond signals indicative of a position of the mower deck; a pluralityof motors coupled to the adjustable linkage and configured to actuatethe adjustable linkage to adjust a supported position of the mower deckwith respect to the chassis; and a controller configured to: determine,based on the first signals and the second signals, a supported positionof the mower deck with respect to the chassis; determine, based on thedetermined supported position of the mower deck, whether realignment ofthe mower deck is warranted in order for the adjustable linkage tomaintain the mower deck in a desired, cutting position of the mower deckabove the lawn, wherein the desired, cutting position is associated withan even cut of the lawn; and in response to determining that realignmentof the mower deck is warranted, generate control signals for theplurality of motors that cause the plurality of motors to actuate theadjustable linkage and realign the mower deck with respect to thechassis.
 2. The lawn mowing apparatus of claim 1, wherein: the firstposition sensor is configured to generate the first signals such thatthe first signals are indicative of pitch and roll of the chassis; thesecond position sensor is configured to generate the second signals suchthat the second signals are indicative of pitch and roll of the mowerdeck; and the controller is further configured to: determine adifferential pitch and a differential roll based upon the pitch and rollfor the chassis and mower deck; and determine that realignment of themower deck is warranted in response to the differential pitch or thedifferential roll exceeding a respective threshold.
 3. The lawn mowingapparatus of claim 1, wherein: the first position sensor is configuredto generate the first signals such that the first signals are indicativeof yaw, pitch, and roll of the chassis; the second position sensor isconfigured to generate the second signals such that the second signalsare indicative of yaw, pitch and roll of the mower deck; and thecontroller is further configured to: determine a differential yaw, adifferential pitch, and a differential roll based upon the yaw, pitchand roll for the chassis and mower deck; and determine that realignmentof the mower deck is warranted in response to the differential yaw, thedifferential pitch, or the differential roll exceeding a respectivethreshold.
 4. The lawn mowing apparatus of claim 1, wherein thecontroller is further configured to: determine a tilt of the chassisbased on the first signals and a tilt of the mower deck based on thesecond signals; and determine that realignment is warranted in responseto determining a difference between the tilt of the chassis and the tiltof the mower deck exceeds a threshold.
 5. The lawn mowing apparatus ofclaim 1, wherein: the plurality of wheels include a back wheelpositioned toward a back of the chassis and a front wheel positionedtoward the front of the chassis; and the adjustable linkage positionsand supports the mower deck under the chassis between the back wheel andthe front wheel.
 6. The lawn mowing apparatus of claim 1, furthercomprising: a plurality of inflatable tires mounted to the plurality ofwheels; wherein the controller is further configured to generate a tirepressure warning in response to determining, based on the first signals,that at least one of the plurality of inflatable tires has an improperair pressure.
 7. The lawn mowing apparatus of claim 1, wherein thecontroller is further configured to generate a deck misalignmentnotification in response to determining that realignment of the mowerdeck is warranted.
 8. The lawn mowing apparatus of claim 1, furthercomprising: a graphical display; wherein the controller is furtherconfigured to cause the graphical display to present a graphicalrepresentation of the determined supported position of the mower deck.9. The lawn mowing apparatus of claim 1, further comprising: a wirelesscommunication interface; wherein the controller is further configured totransmit data indicative of the determined supported position of themower deck via the wireless communication interface.
 10. A method for acontroller of a lawn mowing apparatus, the method comprising: receiving,from a first sensor on a chassis of a lawn mowing apparatus, firstsignals indicative of a position of the chassis; receiving, from asecond sensor on a mower deck of the lawn mowing apparatus, secondsignals indicative of a position of the mower deck, wherein the mowerdeck is positioned under and carried by the chassis via an adjustablelinkage; determining, with the controller based on the first signals andthe second signals, a supported position of the mower deck with respectto the chassis; generating, with the controller a realignmentnotification, in response to the controller determining, based on thedetermined supported position, that realignment of the mower deck iswarranted in order for the adjustable linkage to maintain a desired,cutting position of the mower deck above the lawn, wherein the desired,cutting position is associated with an even cut of the lawn; andgenerating control signals that cause a plurality of motors of the lawnmowing apparatus to realign the mower deck with respect to the chassis.11. The method of claim 10, further comprising: determining adifferential pitch and a differential roll based upon pitch and roll forthe chassis and the mower deck based on pitch and roll indicated by thefirst signals and the second signals; and determining that realignmentof the mower deck is warranted in response to the differential pitch orthe differential roll exceeding a respective threshold.
 12. The methodof claim 10, further comprising: determining a differential yaw, adifferential pitch, and a differential roll based upon yaw, pitch, androll for the chassis as indicated by the first signals and yaw, pitch,and, roll for the mower deck as indicated by the second signals; anddetermining that realignment of the mower deck is warranted in responseto the differential yaw, the differential pitch, or the differentialroll exceeding a respective threshold.
 13. The method of claim 10,further comprising: determining a tilt of the chassis based on the firstsignals; determining a tilt of the mower deck based on the secondsignals; and determining that realignment is warranted in response todetermining a difference between the tilt of the chassis and the tilt ofthe mower deck exceeds a threshold.
 14. The method of claim 10, furthercomprising generating a tire pressure warning in response todetermining, based on the first signals, that an inflatable tiresupporting the chassis has an improper air pressure.
 15. The method ofclaim 10, further comprising generating signals that cause an aircompressor of the lawn mowing apparatus to inflate a tire supporting thechassis in response to determining, based on the first signals, that thetire has an improper air pressure.
 16. The method of claim 10, furthercomprising displaying on a graphical display of the lawn mowingapparatus a graphical representation of the determined supportedposition of the mower deck.
 17. The method of claim 10, furthercomprising transmitting, via a wireless communication interface of thelawn mowing apparatus, the determined supported position of the mowerdeck.